Two-cycle internal combustion engine



TWO-CYCLE INTERNAL COMBUSTION ENGINE Filed June 15, 1938 2 Sheets-Sheet 1 INVENTOR #62275 Z/Eererr BY MDQMHMJEW ATTORNEYS Patented Jan. 14, 1941 UNITED STATES TWO-CYCLE INTERNAL COIMBUSTION ENGINE Han Lieberlierr, Winterthur, Switzerland, assignor to Sulzer Freres. Soeit Anonyme, Winterthur, Switzerland Application June 15, 1938, Serial No. 213,755

In Switzerland June 30, 1937 7 Claims.

The inventionrelates to a two-cycle internalcombustion engine having the admission ports for the scavenging and charging air arranged opposite to the exhaust ports. The invention relates 5 particularly to two-cycle internal-combustionengines in which the admission ports open only after the exhaust ports have been opened and pressure equalization has become established in the cylinder.

It is known that once a jet of air is in motion it can be deflected from its path of motion by another jet of air only with an extraordinarily large expenditure of energy. In the scavenging of engines operating on the two-cycle system, the flow 15 which is the first to be established in the cylinder predominates throughout the scavenging period.

In those engines in which cross-scavenging streams of air may enter first from the middle ports, the scavenging from those ports will prevail 20 during the entire duration of the scavenging period with the air directed as a jet towards the opposite cylinder .wall. The streams emerging from the lateral, rearwardly disposed ports have a small effect.

' It is an object of the invention to so construct and arrange the engine cylinder and its associated means for the admission of scavenging and charging air (hereinafter called admitted-air) that theair is charged through the middleports 39 at least simultaneously with, or even slightly later than, the air charged through the other ports.

In accordance with invention, air control ducts of approximately equal length are provided which connect the cylinder admission ports to a source of air under pressure, with the result that the air is charged into all of the admission portsor slots in the cylinder simultaneously and with equal intensity. The admission ports are preferably divided into groups and each group is connected to a duct about equal to about the length of the other ducts. The ducts may be arranged completely within the cylinder jacket and equality of length may be attained by means of a baille positioned in front of the admission ports which are closest to the supply of air. The ducts leading to the outermost ports may extend approxi- -mately horizontally and those to theinner ports may be slantwise disposed for the purpose of pro- Fig. l is a vertical section through a cylinder in one embodiment of the invention; I Fig. 2 is a horizontal section along line 2-2 of 18. 1:

Fig. 3 is a vertical section through a cylinder in another embodiment of the invention, along line 3-3 of Fig. 4, and Fig. 4 is a horizontal section along line 44 of Fig. 3.

In the construction and arrangement of apparatus illustrated in Figs. 1 and 2, the cylinder I is surrounded by a jacket 2, having a cylinder head 3 in which a fuel-admission valve 4 is mounted. A conduit 5 is arranged on the ad-" mission side of the cylinder for the supply of admitted-air under a suitable working pressure, and exhaust ports 6 are located on the opposite side of the cylinder and adapted to discharge into an exhaust passageway to which leads to an exhaust conduit (not shown).- The admission side of the cylinder is provided with 'a plurality of spaced slots or ports in separate groups III, II and 12 for the admission of air from the conduit 5.

In accordance with the invention the air paths leading from the conduit 5 to the ports l0, II and 26 I2 are arranged in such a manner that they all have about the same length so that the air is admitted to each of the ports III, II and i2 at about the same time and with equal intensity. The separate groups of ports I 0, II and I 2 connect to 30 the conduit 5' by means of ductsv'l, 8 and 9, respectively. The ductsare formed by the partition members 13 and II, one end of each member bearing against the cylinder and the opposite ends extending into the conduit 5. The ducts I, 8 and 9 formed by these members are of approximately equal lengths due to the form of the members and the extent to which they project into the conduit 5. The ducts leading to the outermost ports l2 may be disposed approxi- 40 mately horizontally or, depending on conditions, may even slope slightly upwardly, those leading to the inner ports may slant from the bottom upwardly depending upon exigencies of construction. Figs. 3 and 4 illustrate a form of construction in which'the ducts for the admission 01' air are arranged within the cylinder jacket; The air admitted to the ports ill from the air conduit 5 is supplied through ducts I5 which are formed by the cylinder, the cylinder jacket, and a baflle it which may be integral with the Jacket and which engages the cylinder. In this constructionalso, the air is admitted to all the ports simultaneously and with equal intensity.

position in Figs. 1 and 3.

While the engine illustrated has open ducts leading directly to the air conduit without control or valve means, it is to be understood that the principles of the invention are applicable to engines in whichone or more of the ducts is controlled by valve means.

I claim:

1. In a two-cycle internal-combustion engine having the admission ports in the cylinder arranged oppositely to the exhaust ports in the cylinder, the improvement which comprises a conduit for supplying air under a suitable-pressure to the admission ports, ducts for supplyin the ports with air from the conduit, said admission ports being divided into groups and each group being connected to one of the ducts, said ducts providing separate passages of approximately equal length for the supply air from the conduit to the admission ports, the ducts leading to the ports farthest from the conduit being substan-- tially horizontal and the ducts leading to the ports nearest to the conduit being steeply inclined, whereby the air is'admitted to the cylinder from all the admission ports at about the same time and with about equal intensity.

2. In a two-cycle internal-combustion engine having the admission ports in the cylinder arranged oppositely to the exhaust ports in the cylinder, the improvement which comprises conduit means for supplying air under a suitable pressure to the admission ports, a plurality of partitions of approximately equal length extending from the cylinder into the conduit means, a duct on each side of each partition of approximately equal length connecting the admission ports to the conduit means, whereby the air is admitted to the cylinder from all the admission ports atabout the same time and with about equal intensity.

3. Anengineaccordingtoclaim2inwhichthe ports are divided into groups and each group of ports'is supplied with air by one of the ducts.

4. An engine according to claim 1 in which the cylinder is surrounded by a cylinder jacket, and the ducts are positioned within the cylinder jacket;

5. An engine according to claim 1 in which the duct means are formed by spaced members which ing divided into separate groups of ports, a duct' leading from each group of ports .into the conduit, all of said ducts being oi approximately the same length, whereby the air is admitted to the cylinder from all the admission ports at about the same time and with about equal intensity, and a cylinder jacket surrounding the. cylinder, said ducts being positioned within the jacket.

7. In a two-cycle internal-combustion engine having the admission ports in the cylinder arranged oppositely to the exhaust ports in the cylinder, the improvement which comprises a conduit for supplying air under a suitable pressure to the admission ports, a plurality of partition members extending from the cylinder into the conduit varying distances and forming ducts extending from the admission ports into the conduit that are all of approximately the same length, whereby the air is admitted to the cylinder from all of the admission ports at about the same time and with about equal intensity.

HANS IIEBERHERR. 

